20213712 has 70 divisors (see below), whose sum is σ = 58753122. Its totient is φ = 6734016.

The previous prime is 20213689. The next prime is 20213717. The reversal of 20213712 is 21731202.

It can be written as a sum of positive squares in only one way, i.e., 16842816 + 3370896 = 4104^2 + 1836^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20213717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 10798 + ... + 12530.

Almost surely, 2^20213712 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20213712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29376561).

20213712 is an abundant number, since it is smaller than the sum of its proper divisors (38539410).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20213712 is an equidigital number, since it uses as much as digits as its factorization.

20213712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1759 (or 1738 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 20213712 is about 4495.9661920437. The cubic root of 20213712 is about 272.4051775685.

Adding to 20213712 its reverse (21731202), we get a palindrome (41944914).

The spelling of 20213712 in words is "twenty million, two hundred thirteen thousand, seven hundred twelve".